That's pretty much it Jim, except most of the time, for my own anyway, I build the entire prop framework with steel, and then simply 'cover' it with wood or some other type of a more indestructable material rather than trying to re-work an existing piece of furniture.
Go to:http://tinyurl.com/2hq49m
And scroll through to see:
Bed
Juke Box
Pinball Machine
Chair

All of these are built with a steel tube frame, and then covered with 1/4" or 1/8" hardboard.

I usually make an overview of the whole haunt, then seperate ones for each room. Mark where the scares are, electrical outlets, lights, etc. If possible, make hallways for staff to get from room to room.

not so much the prop but the joke, got a Seeburg been restoring here and there (as in way distant future). Wantred to get a Rockola Princess model someday. So the name gig had me in hysterics. Thanks on the thought though, wont be able to drive from Socal anytime soon though